Mediating Effects of Fitness-For-Work on Fatigue for Mining (Heavy Equipment) Technicians in Indonesia

Yusuf Nugroho Doyo Yekti,Khoirul Muslim,Yassierli 대한산업공학회 2022 Industrial Engineeering & Management Systems Vol.21 No.4

Fatigue has been considered as a major contributing factor to workplace accidents. While most previous studies on fatigue have been conducted in a laboratory setting, the current study was performed in the mining region of Kali-mantan, Indonesia. This study assessed the fitness-for-work and fatigue experienced by 21 maintenance technicians at two mining workshops. This study focused on three independent variables: work shift (day shift and night shift), work locations (non-remote area and remote area), and individual fitness. Heart rate and the Psychomotor Vigilance Test (PVT) data (in terms of total error and mean reaction time) were collected at the beginning, middle, and end of work. Covariance analysis was applied to determine the effect of the independent variables on fitness-for-work and fatigue. The results show that work shift and individual fitness significantly influence fitness-for-work (p < 0.05). However, none of the independent variables significantly affect fatigue, even though fitness-for-work and fatigue are strongly correlated (r = 0.69, p < 0.05). These results proved the role of fitness-for-work as an intermediate factor in fatigue. We suggest that there should be a shift in strategy for reducing the risk of accident-related fatigue, from fa-tigue monitoring directly to fitness-for-work screening. Eventually, the practical implementations of the findings are discussed comprehensively.

Development of a Training System for Lathe Operation Using a Simulator with Relationship between Speed of Tool Feed and Cutting Sound/Shape of Chips

Kawashimo, Takashi,Doyo, Daisuke,Yamaguchi, Tatsuya,Nakajima, Ryosuke,Matsumoto, Toshiyuki Korean Institute of Industrial Engineers 2015 Industrial Engineeering & Management Systems Vol.14 No.2

The recent manufacturing industry in Japan has found it difficult to transfer skills from trained workers to inexperienced workers because the former ages and then retires. This is a particular problem for lathe process, as this operation requires explicit and tacit knowledge, and defining the skills clearly in a manual is difficult. This study aims to develop a training system for lathe operation by using a simulator; this includes formulas that help define the relationship between the speed of tool feed and cutting sound/shape of chips which were proposed in the preceding study. The developed training system is verified the effectiveness.

Development and Implementation of a Skill Transfer System for a Self-Tapping Screw-Tightening Operation

Matsumoto, Toshiyuki,Doyo, Daisuke,Shida, Keisuke,Kanazawa, Takashi Korean Institute of Industrial Engineers 2011 Industrial Engineeering & Management Systems Vol.10 No.3

Self-tapping screws have some operational peculiarities. In spite of their economical advantage that requires no prior tapping operation, a weakness of self-tapping screw-tightening operations is that screws can easily be tightened at a non-right angle, thus resulting in an improper tightening strength. Increases in outsourced workers have reduced labor costs, but the accompanying high worker fluidity means that new workers are more frequently introduced into factories. It is necessary to train new workers for self-tapping screw-tightening operations, which occupies a considerable portion of ordinary assembly works. The purpose of this study is to develop and implement a skill transfer system for the operation. This study (1) proposes a set of characteristic values for evaluating the quality of the operation and develops a device that can measure these values; (2) proposes criteria for evaluating the resultant quality of the tightening; and (3) develops a skill training system for better work performance. Firstly, sets of characteristic values for evaluating the quality of the operation, namely, torque, vertical pressure forces and horizontal vibration forces, are proposed. A device that can measure these values is developed. Secondly, criteria for evaluating the resultant quality of the tightening are identified, involving tightening torque, maximum vertical pressure and timing, vibration area during the processing and tightening period, and work angle. By using such parameters, workers with the proper aptitude can be identified. Thirdly, a skill training system for the operation is developed. It consists of screwdriver operation training and screw-tightening training with feedback information about the results of the operation. Finally, the validity of the training system is experimentally verified using new operators and actual workers.

Development of a Training System for Lathe Operation Using a Simulator with Relationship between Speed of Tool Feed and Cutting Sound/Shape of Chips

Takashi Kawashimo,Daisuke Doyo,Tatsuya Yamaguchi,Ryosuke Nakajima,Toshiyuki Matsumoto 대한산업공학회 2015 Industrial Engineeering & Management Systems Vol.14 No.2

The recent manufacturing industry in Japan has found it difficult to transfer skills from trained workers to inexperienced workers because the former ages and then retires. This is a particular problem for lathe process, as this operation requires explicit and tacit knowledge, and defining the skills clearly in a manual is difficult. This study aims to develop a training system for lathe operation by using a simulator; this includes formulas that help define the relationship between the speed of tool feed and cutting sound/shape of chips which were proposed in the preceding study. The developed training system is verified the effectiveness.

Development and Implementation of a Skill Transfer System for a Self-Tapping Screw-Tightening Operation

Toshiyuki Matsumoto,Daisuke Doyo,Keisuke Shida,Takashi Kanazawa 대한산업공학회 2011 Industrial Engineeering & Management Systems Vol.10 No.3

Self-tapping screws have some operational peculiarities. In spite of their economical advantage that requires no prior tapping operation, a weakness of self-tapping screw-tightening operations is that screws can easily be tightened at a non-right angle, thus resulting in an improper tightening strength. Increases in outsourced workers have reduced labor costs, but the accompanying high worker fluidity means that new workers are more frequently introduced into factories. It is necessary to train new workers for self-tapping screw-tightening operations, which occupies a considerable portion of ordinary assembly works. The purpose of this study is to develop and implement a skill transfer system for the operation. This study (1) proposes a set of characteristic values for evaluating the quality of the operation and develops a device that can measure these values; (2) proposes criteria for evaluating the resultant quality of the tightening; and (3) develops a skill training system for better work performance. Firstly, sets of characteristic values for evaluating the quality of the operation, namely, torque, vertical pressure forces and horizontal vibration forces, are proposed. A device that can measure these values is developed. Secondly, criteria for evaluating the resultant quality of the tightening are identified, involving tightening torque, maximum vertical pressure and timing, vibration area during the processing and tightening period, and work angle. By using such parameters, workers with the proper aptitude can be identified. Thirdly, a skill training system for the operation is developed. It consists of screwdriver operation training and screw-tightening training with feedback information about the results of the operation. Finally, the validity of the training system is experimentally verified using new operators and actual workers.

Automation of Decision-Making in the Game "Ecopoly" for Education on Relationship between Environment and Economy

Tatsuya Komuro,Ayano Shinozaki,Aramu Kim,Daisuke Doyo,Toshiyuki Matsumoto 대한산업공학회 2012 Industrial Engineeering & Management Systems Vol.11 No.1

Recently, global environmental problems have become serious due to human economic activities. Therefore, in order to build a sustainable society in which human economic activities coexist with nature, it is important to promote and enhance environmental education. As a preceding study, a board and computer game of "Ecopoly," which is the game for education on global environmental problems, were developed. This study further aims to develop algorithms which make decisions in Ecopoly, to automate decision-makings of opponents using the algorithms, and to develop the environmental educational game "Ecopoly V" which enables self-learning. In order to develop the algorithms, the board game of Ecopoly was played, and each player"s decision-makings at the all points at which players make a decision were observed and analyzed. From the analyses, it became clear that the decision-makings were distinguished by 3 characteristics; Ecology type, Economy type, and Balance type. Based on the characteristics, the factors and standard values of each decision-making were made clear. Algorithms were developed based on the factors and standard values. Ecopoly V was developed by incorporating the algorithms into the computer game of Ecopoly. Experimental testing of the game was conducted and the validity of the game was verified.

Automation of Decision-Making in the Game "Ecopoly" for Education on Relationship between Environment and Economy

Komuro, Tatsuya,Shinozaki, Ayano,Kim, Aramu,Doyo, Daisuke,Matsumoto, Toshiyuki Korean Institute of Industrial Engineers 2012 Industrial Engineeering & Management Systems Vol.11 No.1

Recently, global environmental problems have become serious due to human economic activities. Therefore, in order to build a sustainable society in which human economic activities coexist with nature, it is important to promote and enhance environmental education. As a preceding study, a board and computer game of "Ecopoly," which is the game for education on global environmental problems, were developed. This study further aims to develop algorithms which make decisions in Ecopoly, to automate decision-makings of opponents using the algorithms, and to develop the environmental educational game "Ecopoly V" which enables self-learning. In order to develop the algorithms, the board game of Ecopoly was played, and each player's decision-makings at the all points at which players make a decision were observed and analyzed. From the analyses, it became clear that the decision-makings were distinguished by 3 characteristics; Ecology type, Economy type, and Balance type. Based on the characteristics, the factors and standard values of each decision-making were made clear. Algorithms were developed based on the factors and standard values. Ecopoly V was developed by incorporating the algorithms into the computer game of Ecopoly. Experimental testing of the game was conducted and the validity of the game was verified.